Arc lamp



Oct. 26, 1926. C. A. GREEN ET AL ARC LAMP Filed April 11. 1924 15007120713 ha/fies a G/wan fix/ M JflB/ m/c.

Patented Get. 26, 192.6.

um'rs smash air CHARLES A. GREEN AND HAROLD J. BRUNK, OF CHICAGO, ILLINOIS, ASSIGNORE TO 0. F. PEASE COMPANY, A CORPORATION OF ILLINOIS.

ino LAMP.

Application filed. April 11, 1924. Serial No. 705,771.

This invention relates to improvements in electric arc lamps such as used in the blue printing, photo engraving and other arts, and more particularly to a globe holder for such lamps.

In arc lamps of the type described, the globe is supported between top and bottom holders, one of which, usually the bottom holder, is normally fixed, but adjustable to permit of the globe being positioned and removed. Both holders are generally carried by a common frame member. In practice, these lamps are used singly for certain kinds of work, but for other kinds of work a battery of lamps, grouped rather closely, is used. In each instance the temperature rises to quite a high degree and especially is this true when the lamps are used in battery formation where each is not only subject to its own heat, but also to the heat developed by the adjacent lamps. V

The are lamps are grouped closer together in blue printing than in other arts, which increases their temperature, in addition to the fact that more current is used per lamp than under normal conditions. They are especially so designed in order to give a better color value to the light with the arcs at high temperatures. The high temperatures cause expansion, which is greater in the globe than in the member which carries the holders and in consequence the hot globe bulges out of shape. Upon subsequent contraction therefore, the seal between the globe and the holders is disturbed and leakage of air into the globe occurs resulting in wasteful consumption of carbon and bowing of the arc to one side causing localized heating of the glass and breakage, necessitating frequent renewals and materially increasing the cost of operation. The present invention contemplates the provision of a resilient or yielding holder for the globe which will elfectively maintain the seal at both ends thereof at all times through the action or upward pressure of a spring member, thus preventing breakage, such as above described.

Other objects and advantages of the in vention will be apparent from the follow ing description taken in connection with the accompanyingdrawings, wherein one form of the invention is illustrated.

In the drawings:

Fig.1 is a front elevation of a battery of are lamps as used in the blue printing art, for instance. a

F 1g. 2 1s a longitudinal sectional view of a holder constructed in accordance with the present invention.

Fig. s a: top plan view thereof. In Fig. 1 the are lamps 10 are arranged in a group as used in blue printir'igmachinesv and are shown mounted on a transverse pipe or conduit 11, said lamps comprising the carbons 12 and 18, the controlling andfeeding mechanism 14, globe 15 and reflector 16. The globe is confined between top and bottom holders 17 and 18, respectively. These holders are usually carried by a common frame, not shown in the drawings;

According to the presentinvention, the lower globe holder is made yieldable so as to maintain an air tight seal at bottom of the dimensional variations therein 0 changes in temperature. To this end the hold-er 18 is in the form of a plug-like member flared outwardly at its upper end, as at 19, and screw-threaded at its lower end, as at 20, for engagement with a suitable screw threaded aperture in the lower supportingthe top and casioned by leg of the frame member, not shown, which carries both holders. This plugdike member is provided with a central opening 21 extending therethrough which accommodates the lower carbon 13. At its lower end opening 2-1 is flared outwardly and screwthreaded, at at 22, for receiving the 10 ver carbonholder 23. An annular chamber 24. is provided in the. upper end of the plug-like support 18 and an inner tube 25 is provided which forms a wall common to both chamber 24 and the central opening 21. The chamber 24 extends below the outwardly flared portion 19 of the support, providing a downward extension of the chamber in the form of an annular groove 26. A movable supporting plate 27, centrally apertured to permit of the inner tube 25 projecting therethrough, is mounted in the chamber 2% and is accurately machined around its inner and outer peripheries for snug engagement with the inner tube'25 and the outer wall of chamber 24, respectively. A coiled spring 28 seats down into annular groove 26 at its lower end and engages upwardly against the under face of plate 27 at its upper end. Thus the plate floats on the spring and if the ends of the globe are not entirely square globe. at all times despiteedge of the globe.

changes in temperature and that the plate is free to tilt slightly and thus eifect a sealing of the ends of the globe just as eiiiciently as in cases where a perfect globe is encountered. In order to permit this tilting of the plate despite the snug fit thereof in chamber 24, the inner periphery thereof is reduced or beveled, as at 27 and the outer periphery is rounded, as at 2?". Lateral retaining lugs 29 are pressed outwardly from the upper edge of the inner tube 25 to prevent displacement of plate 27, and also to limit its upward travel.

In practice, the holder 18 is first screwed into engagement with the; screw-threaded opening provided in the lower end of the common member which carries both globe holders, the globe is then moved into engagement with the top holder 17 and then the lower end of the globe is swung into position over the holder 18, the latter being then adjusted upwardly until plate 27 has been brought into firm engagement with the lower To facilitate adjusting the holder 18 the same is knurled, as at 29.

It will. be obvious from the foregoing that plate 27 upon which the globe rests when in position will be held in sealing engagement with said globe by the spring 28 at all times, despite dimensional variations occasioned byv said spring will also function to maintain a similar engagement between the upper end of the globe and top holder 17. The plate 27, as previously described, is accurately machined around its inner and outer peripheries so as to snugly lit the walls of chamber 24 to thus minimize leakage of air into the globe between plate 27 and the inner tube 25. When it is desired to remove the globe for any reason, the support 18 is screwed down until the lower end of the globe will clear said support after which it is swung to one side and removed.

It will be obvious to those skilled in the art that the invention is susceptible of various changes and modifications, and. accordingly it is not desired to limit or restrict the same to the particular form or arrangement of parts herein illustrated except where limitations appear in the ap iended claims.

What we claim is 1. -A globe holder for are lamps comprising a plug-like member having acentral opening therethrough, and a chamber in its upper end, an inner tube providing a wall common to both the opening and the chamber, a plate in said chamber provided with an opening through which said tube projects, and resilient means interposed between said plate and the bottom of said chamber.

2. A globe holder for are lamps comprising a plug-like member having a central opening therethrough a carbon holder closing the lower end of said opening and a chamber in its upper end, an inner tube providing a wall common to both the opening and the chamber, a plate in said chamber provided with an opening through which said tube projects, resilient means interposed between said plate and the bottom of said chamber, and means for limiting the upward movement of said plate.

3;A globe holder for are lamps comprising a plug-like member having a central opening therethrough and a chamber in its upper end, an inner tube providing a wall common to both the opening and the chamher, a plate in said chamber provided with an opening through which the tube projects, resilient means interposed between said plate and the bottom of said chamber, and means for limiting the upward movement of said plate, said means being in the form of laterally projecting lugs carried at the upper end of said tube.

V a. A globe holder for are lamps comprising a pluglilre member having a chamber in its upper end, a plate in said chamber fitting the same snugly to form a sliding contact permitting substantially no leakage of air therethrough, resilient means interposed between said plate and the bottom of said chamber, and means for limiting the upward movement of said plate.

5. A globe holder for are lamps comprising a member having a screw threaded extension, an annular recess in the other end thereof, an extension of said recess forming a seat for a spring, a helical spring on said seat, and a ring having a slidingseat in said annular recess, said ring resting on said spring and forming a yielding seat for said globe.

6. A globe holder for are lamps comprising a member having a screw threaded exten sion, an annular recess in the other end thereof, an extension of said recess forming a seat for a spring, a helical spring on said seat, a ring having a sliding seat in said an nular recess, said ring resting on said spring and forming a yielding seat for said globe and being beveled at its inner edge and rounded at its outer edges to permit tilting thereof, without permitting substantial leakage of air past said edges into said globe.

7. A globe holder for are lamps comprising a plug-like member having a central opening therethrough, and a chamber in its upper end, an inner tube providing a wall common to both the opening and the chamher, a plate in said chamber provided with an opening through which said tube projects,

resilient means interposed between said plate and the bottom of said chamber, and a removable carbon holder held inthe lower end of said tube.

In testimony whereof,

our names. I

CHARLES A. GREEN. HAROLD J. BRUNK.

we have subscribed 

